Removable supporting-form for concrete.



J.- B. BLAW. BEMOVABLE SUPPORTING FORM FOR CONCRETE.

APPLICATION FILED HAY 15, 1907.

INVENTOR Patented Oct. 18,1910.

Ni STATES AEN FF C JACOB B. BLAW, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO BLAW COLLAPSIBLE STEEL GENTERING COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION or NEW JERSEY.

Specification of Letters Patent.

Patented Oct. 18, 1910.

Application led May 15, 1907. Serial No. 373,732.

To all whom limag concern.'

Be lt known that I, JACOB B. BLaw, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Remov-able Supporting-Forms for Concrete, of which the following is a specification. A My invention relates .to collapsible forms for use in the construction of concrete sewers, subways, and the like, and has for its objects; to provide a form which can be more conveniently handled and operated than those heretofore employed; to provide a collapsible form wherein the circumferential stiffening members form a portion of the outer surface of the form, and are flush with the outer surfaces of the intermediate plates, and, to provide a vknock-down form wherein the plates may be detached from the stilfening members, and removed after the concrete has set without altering the posit-ion of the stiiening members. One form of the apparatus is shown'in the accompanying drawings, wherein z- F igurepl is a transverse section through a completev form,

Figure 2 is a longitudinal section through the form on t-he line II-II of Figure l,

Figure 3 is an enlarged detail section on the line III-III-of Figure 2, wherein the method of securing the plates to the stiftenin members is illustrated, and

ligure 4 is an enlarged detail section on the :line IV-IV of Figure 2, which section shows the method of securing the plates to the stitfening members, and the means for attaching the braces to the'stilfening members.

The mold in its preferred fini, comprises a series of circumferential T members or sections spaced apart longitudinally the length of the plates to be usedintermediate the T sections, which plates abut against the T ribs' at theirrends and are detachably secured thereto, so that after the concrete has set about the form or mold the plates may be detached' from the T sections, after which the T sections themselves may be detached from the concrete. In operation, the T sections are placed in position and the plates gradually built up commencing at the bottom and filling in behind the plates as they are placed in position.

Referring to the drawings, l are the circumferential T sections, which as indicated in Figure 2, are spaced apart a distance equal to the length of the sectional plates, 2 are the plates interposed between the T sections 1, which plates are bent to the desired radi-us to yfit the curve of the T sections, 3 are the plates for overlapping the inside edges of the T sections as indicated in Figure 3, which plates are bolted along the vertical edges of the plates 2 and are spaced away therefrom suh a distance as is necessary to make the outer surface of the plates iush with the outer surface of the T sections by means of the liners 4, 5 are staples secured along the edges of the T sections l, and projecting through slots in the edges of the plates 3, 6 are wedges which are driven through the staples or loops 5 for clamping the plates 3 to the edges of the'T sections, 7 are stifening plates which are bolted along the inwardly projecting flanges of the T sections when the forms are of large diameter, 8 are longitudinally extending angle sections bolted to a plurality of the inwardly projecting flanges of the T members by means of the angle clips 9 (see Figure 4e), 10 are cross braces preferably of angular cross section, which braces are applied intermediate the ends of the longitudinal angle members 8 as indicated in Figures 2 and 4, 11 are longitudinal extending timbers upon which' the weight of the form is carried, 12 are the wedges whose removal after the cement has set permits the timbers l1 todrop slightly thereby freeing the stili ening members l, and 13 are the cross mem- .bers upon the floor of the sewer for bracing the timbers 11, and holding thevarious parts intheir proper position. In order that the horizontal edges of the platee 2 may be flush and even the overlapping strips l covered with concrete.

14 are employed (Figure 2) which strips are riveted to the edge of one member and adapted to overlap the edge of the opposing plate and thereby hold the plates 1n alinement.

The operation in using the form is as follows. the oor and the timbers 1l and 13 positioned thereon, after which the T sections 1- are placed in position at proper intervals and secured by means of the longitudinal connecting angles 8 and the cross braces 1Q. 'lhe lowermost plates 2 are then put in position with their inner edges abutting against the edges of the T sections, and the plates 3 overlapping the inside edges ofthe T sectionswith their perforations engaging the loops 5, after which the wedges are driven into position thus tightly clamping the edges of the plates 2 in the position shown in F1gures 3 and 4` Concrete is now filled in behind this lower row of plates until it approaches the upper edges thereof, when another series -of plates are added and the filling-up operation continued. This operation is contmued until the plates are all in position and all The operation will be carried on simultaneously with as many lenvths of plates as can be conveniently handle After'the concrete has set about the form, the plates 2 are released from the stiifening sections l by removing the wedges 6 whereupon the plates can be pulled away from the concrete. After the plates have been removed from the stiffening sections 1, such sections can be freed from the concrete by removing the wedges 12 thus ermitting the timber 11 to fall down and provides room for the freeing of the stifening sections.

lt will be apparent from the foregoing descriptionA that the plates 2 are held se- `curely with their outer surfaces fiush with the outer surfaces of the stitfening sections 1, and that the outer surfaces of the stiening sections constitute a portion of the outer surface of the form thus reducing the cost of the mold or form to a figure less than where the stiffening sections act merely as ribs, and in which the covering plates come together at the rear of the sti'ening sections. Furthermore it will be apparent that by having the plates set to abut against the edges of the stilfening sections 1, such plates 2 may be removed gradually and safely without moving the sections 1, which result ca'nnot be attained where the plates overlap the outside of the members 1 in the `old type of-molds, and wherein it is necessary to remove the supporting sections before any of the plates can be det-ached from the concrete. In other words in the old type of mold -the removal of the supporting ribs A layer of concrete is first laid for.

meant the freeing of all the plates carried thereby simultaneously, which condition obviously endangered the workmen because of their inability to attend to all of the plates freed and the danger of accidental falling of a part of the plates 'While other of the plates were being loosened from the concrete. overcome in my construction, and that the plates may be removed gradually one at a time. 1t will be apparent that the stiftening T sections need lnot necessarily be integral commercial Ts but may, if desired, be Ts built up from angles, and the term T section as used in the claims is intended to cover the. T structure broadly.

Having thus described my invention and lt will be seen that this danger is.

illustrated its use, what I claim as new and desire to secure by Letters Patent is the following 1. A mold or form comprising alternate circumferential stilening members with inwardly projecting ianges and plates interposed therebetween, strips extending along the vertical edges thereof, and means for detachably securing the strips to the webs of the stiffening members with the .outer surfaces of the plates in alinement with the outer surfaces of the webs of the stifening members.

2. A form or mold comprising spaced T sections with inwardly projecting flanges and a plurality of plates extending between the edges of the webs of the T sections, strips extending along the edges of said plates overlapping the webs of the T sections, and means for detachably clamping the edges of the strips to the webs of the T sections so that the outer surfaces of the plates and the T sections are flush.

3. A form4 or mold comprising spaced T sections and a plurality of plates extending between the edges of the T sections, and strips extending the width of the plates for detachably securing the plates to the inner edges of the T sections with the edges of such plates abutting the 'edges of the T sections and their outer surfaces Hush with the outer surfaces of the T sections.

4. A removable form or mold comprising and provided with perforated plates for encured to such longitudinal member and eX- gaging the inner sides of the T flanges, statending to the opposite side of the mold. ples on the T sections extending through the In testimony whereof I have hereunto perforations in the plates, and Wedges for signed my name in the presence of the two engagiig the taples. f 1d subscribed Witnesses.

6. ie com ination in a orm or mo T of stiifening sections arranged With vone JACOB B' BLAY" flange projecting inwardly a longitudinal Witnesses: l section engaging a plurality of the in- J. C. BRADLEY, 10 Wardly projecting anges and a brace se- ARCHWORTH MARTIN. 

